Pest control aerosol sprayer

ABSTRACT

A pest control aerosol sprayer that is free from giving rise to a fire or a burn in its storage or use, includes a pressure-tight container receiving therein a noxious insect behavioral inhibitor of which an active ingredient is HFC-152a acting also as both a propellant and refrigerant. The pressure-tight container has at its top a valve having a stem, and the stem has an injection hole therein that can be opened with the stem forced down. A head cap is attached to a top of the pressure-tight container and is provided with a spray nozzle and an inflow port in which the stem of the valve in the pressure-tight container is fitted. The head cap has an injection passage leading from the inflow port to the spray nozzle.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of U.S. application Ser. No.12/918,117, filed Sep. 7, 2010, now U.S. Pat. No. 8,393,554 which isbased upon and claims the benefit of priority from InternationalApplication No. PCT/JP2009/053797, filed Feb. 24, 2009, which is furtherbased on and claims the benefit of priority from prior Japanese PatentApplication No. 2008-042943, filed Feb. 25, 2008, the entire contents ofall of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a pest control aerosol sprayer, i.e.,an aerosol sprayer for exterminating a noxious insect, comprising apressure-tight container containing therein a noxious insect behavioralinhibitor and a head cap attached to a top of the pressure-tightcontainer and provided with a spray nozzle, for spraying the noxiousinsect behavioral inhibitor in the pressure-tight container through thespray nozzle of the head cap to ex-terminate the noxious insect.

BACKGROUND ART

A pest control aerosol sprayer has so far consisted of a hermeticallyclosed pressure-tight container and a head cap attached to a top of thepressure-tight container.

The pressure-tight container is provided at a top center thereof with avalve including a vertically movable stem, the container containing aninsectifuge therein. The insectifuge contained in the pressure-tightcontainer is a liquid mixture of an insecticide and a liquefiedpetroleum gas (LPG) as its propellant.

Also, the head cap is provided with a spray nozzle directed forwards andon its rear side with an operating button.

And, in an operation of the pest control aerosol sprayer, pressing theoperating button on the head cap by a user pushes down the stem of thevalve in the pressure-tight container to cause the insectifuge containedin the pressure-tight container to be sprayed under its internal gaspressure via the stem of the valve in the pressure-tight container andforwards through and out of the spray nozzle on the head cap.

Such a pest control aerosol sprayer, however, in which the insectifugecontained in the pressure-tight container has an insecticide mixedtherein has had several restrictions. Thus, since the insecticide exertsan adverse effect not a little on the human body, its use in thevicinity of a kitchen where there are foodstuff and tableware likelyinfested with noxious insects gives rise to the problem that theinsecticide in the insectifuge sprayed comes to adhere to foodstuff andtableware. Or its use in a room where there is a baby or small infantdoes the problem that the insecticide comes to be sprayed on the baby orsmall infant. Thus, in the vicinity of a kitchen where there arefoodstuffs and tableware or in a room where there is a baby or smallinfant it has been the actual fact that the pest control aerosol sprayeris refrained from using or is not used at all.

Accordingly, instead of an insectifuge using an insecticide exerting anadverse effect on the human body, it has become known in recent years touse a pest control aerosol sprayer using a noxious insect behavioralinhibitor having a refrigerating effect and little adversely affectingthe human body. To cite an example, as shown in JP 2004-168948 A anoxious insect behavioral inhibitor containing dimethyl ether and wateris used which is caused to attach to a noxious insect to refrigerate thenoxious insect, thereby terminating its behavior, i.e., to kill it byits paralysis.

Such a pest control aerosol sprayer, however, has the problem firstlythat the pressure-tight container to contain the noxious insectbehavioral inhibitor cannot be made of normal steel but must be made ofaluminum to avoid its rusting, corrosion or the like; an aluminum madepressure-tight container is high in price, making the pest controlaerosol sprayer highly expensive. Secondly, the problem is had thatdimethyl ether used in the noxious insect behavioral inhibitor has achemical property that it is exceptionally high in flammability, givingrise in its storage and use to the problem of a fire or burn. Other thandimethyl ether, materials which have been used for the noxious insectbehavioral inhibitor have their flammability as strong as dimethylether, much likely to lead to the problem of a fire or burn.

Also, a pest control aerosol sprayer using an insectifuge having mixedtherein an insecticide, not a noxious insect behavioral inhibitor, islikely to lead to the problem of a fire or burn because of the use asits propellant of a liquefied petroleum gas that is strong inflammability.

Accordingly, it is an object of the present invention to provide a pestcontrol aerosol sprayer for exterminating noxious insects which is freefrom bringing about such problems, in particular the problem of a fireor burn that is its most important matter.

DISCLOSURE OF THE INVENTION

The present invention provides in a first aspect thereof a pest controlaerosol sprayer, which comprises: a pressure-tight container containingtherein a noxious insect behavioral inhibitor of which an activeingredient is an alternative for chlorofluorocarbon acting also as botha propellant and refrigerant, the pressure-tight container having at itstop a valve provided with a stem and in the stem with an injection holethat can be opened with the stem forced down; and a head cap attached toa top of the pressure-tight container and provided with a spray nozzleand an inflow port in which the stem of the valve in the pressure-tightcontainer is fitted, the head cap being formed therein with an injectionpassage leading from the inflow port to the spray nozzle.

The present invention provides in a second aspect thereof a pest controlaerosol sprayer according to the first aspect mentioned above, in whichthe alternative for chlorofluorocarbon that is an active ingredient ofthe noxious insect behavioral inhibitor is HFC-152a.

The present invention provides in a third aspect thereof a pest controlaerosol sprayer according to the first aspect mentioned above, in whichthe alternative for chlorofluorocarbon that is an active ingredient ofthe noxious insect behavioral inhibitor is HFO-1234yf.

The present invention provides in a fourth aspect thereof a pest controlaerosol sprayer according to the first aspect mentioned above, in whichthe alternative for chlorofluorocarbon that is an active ingredient ofthe noxious insect behavioral inhibitor is HFO-1234ze.

The present invention provides in a fifth aspect thereof a pest controlaerosol sprayer according to any one of the first to fourth aspectsmentioned above, in which the injection passage formed in the head capis provided with a pressure reducer means for lowering the pressure of agas prior to its reaching the spray nozzle.

The present invention provides in a sixth aspect thereof a pest controlaerosol sprayer according to the fifth aspect mentioned above, in whichthe pressure reducer means includes injection passages bifurcated intoand provided with at least two spray nozzles whereby the pressure of thegas is lowered prior to its reaching a spray nozzle.

According to the present invention, using a noxious insect behavioralinhibitor of which an active ingredient is an alternative forchlorofluorocarbon acting also as both a propellant and refrigerantallows refrigerating a noxious insect and terminating the behavior ofthe noxious insect, i.e., killing the noxious insect on its paralyzing,thereby exterminating the noxious insects, without adversely affectingthe human body. And, using as the active ingredient of the noxiousinsect behavioral inhibitor, an alternative for chlorofluorocarbon whichhas the chemical property that it is very low in flammability,eliminates the problem such as of a possible fire or burn in its storageor use, and thus serves to provide extremely safe products of a pestcontrol aerosol sprayer.

Also, if the noxious insect behavioral inhibitor is used of which anactive ingredient is an alternative for chlorofluorocarbon such asHFC-152a, HFO-1234yf or HFO-1234ze whose gas pressure is extremely high,the pest control aerosol sprayer equipped with a pressure reducer meanin the injection passage of the head cap allows the pressure reducermeans to lower the pressure of gas prior to its reaching a spray nozzle,thereby rendering the noxious insect behavioral inhibitor in the form ofa mist whose small drops are of a desired particle size for shootingsuccessfully from a spray nozzle.

BRIEF DESCRIPTION OF THE DRAWINGS

In the Drawings:

FIG. 1 is a front view of a pest control aerosol sprayer according tothe present invention;

FIG. 2 is a side view of the pest control aerosol sprayer according tothe present invention;

FIG. 3 is a cross sectional view taken along the line in FIG. 1; and

FIG. 4 is an enlarged cross sectional view illustrating the neighborhoodof a head cap.

BEST MODES FOR CARRYING OUT THE INVENTION

Mention is made of a pest control aerosol sprayer as one form ofimplementation of the present invention.

The pest control aerosol sprayer as shown in FIGS. 1 and 2 consists of ahermetically closed pressure-tight container 1 and a head cap 2 attachedto a top of the pressure-tight container 1.

As shown in FIGS. 3 and 4, the pressure-tight container 1 is provided inan upper and central area thereof with a valve 3 in which a verticallymovable stem 5 having an injection hole 4 is forced upwards by a spring6. The valve 3 is so designed that moving the stem 5 downwards causesthe injection hole 4 in the stem 5 to be opened. The pressure-tightcontainer 1 is made of steel but it does not intend to be limited tobeing so.

And, the pressure-tight container 1 contains a noxious insect behavioralinhibitor A which has an alternative for chlorofluorocarbon acting as anactive ingredient and also as a propellant and refrigerant. Thealternatives for chlorofluorocarbon include hydrofluorocarbon andhydrofluoroolefin and these alternatives for chlorofluorocarbon have achemical property that their flammability is very low. And, as thealternative for chlorofluorocarbon in this form of implementation isused HFC-152a (1,1-difluoroethane) (chemical formula: CHF₂CH₃; CAS No.75-37-6) that is a kind of hydrofluorocarbon. The content of HFC-152a inthe noxious insect behavioral inhibitor A will be described laterherein. While hydrofluorocarbon for use may not necessarily be HFC-152abut may be HFC-134a (chemical formula: CH₂FCF₃; CAS No. 811-97-2) asanother kind thereof, it should most preferably be HFC-152a, taking intoaccount use conditions, operations and effects. However, there are verysuitable ones other than hydrofluorocarbons such as HFC-152a. Forexample, they are as hydrofluoro-olefins, HFO-1234yf(2,3,3,3-tetrafluoropropene) (chemical formula: CF₃CF═CH₂; CAS No.754-12-1) and HFO-1234ze (1,3,3,3-tetrafluoropropene) (chemical formula:CF₃CH═CFH; CAS No. 1645-83-6). Such HFO-1234yf and HFO-1234ze have aglobal warming potential (GWP) lower than that of HFC-152a and also havea chemical property such that they are lower in flammability thanHFC-152a. Moreover, HFO-1234ze is not flammable at all and thusnonflammable. From these reasons it is desirable, too, to use HFO-1234yfand HFO-1234ze as alternatives for chlorofluorocarbon and especially thelatter well, taking into account their chemical properties.

The head cap 2 is provided with a spray nozzle 10 facing forward and ina lower and central area thereof with an inflow port 11 in which thestem 5 of the valve 3 in the pressure-tight container 1 is fitted. Thehead cap 2 is formed with an injection passage 12 extending to the spraynozzle 10 from the inflow port 11. The head cap 2 is further provided onits rear side with an operating button 13.

Instead of the operating button 13 provided on the rear side of the headcap 2, there may be provided a trigger lever on the lower side of thespray nozzle 10 that is a front side of the head cap 2. Also, instead offacing forwards, the spray nozzle 10 may be made to face upwards.

And, as shown in FIG. 4 the head cap 2 is equipped in its internallyformed injection passage 12 with a pressure reducer means for decreasingthe pressure of a gas before it reaches the spray nozzle 10. In aspecific example illustrated as the pressure reducer means, theinjection passage 12 is bifurcated into an upper injection passage 12 aand a lower injection passage 12 b and the spray nozzle 10 is mounted tothe end of each of the upper and lower injection passages 12 a and 12 b.By means of bifurcating the injection passage 12, the pressure of thegas is caused to decrease before it reaches the spray nozzle 10. Forsuch an injection passage 12, let it be here that the injection passage12 prior to bifurcation is of a diameter D of 3 to 4 mm, the upperinjection passage 12 a is of a diameter Da of 1.5 mm and the lowerinjection passage 12 b is of a diameter Db of 1.8 mm. Making the size(diameter Da) of the upper injection passage 12 a little smaller thanthe size (diameter Db) of the lower injection passage 12 b in thismanner allows rendering conditions of spraying from the upper and lowerspray nozzles 10 a and 10 b even and sufficient.

Also, while the pressure reducer means provided in the injection passage12 bifurcates the injection passage 12, it does not intend to be limitedto doing so. The pressure reducer means may bifurcate or divide theinjection passage 12 into three or more passage parts provided withthree or more spray nozzles 10. Further, instead of bifurcating theinjection passage 12, the injection passage 12 may be provided midwaytherein with a pressure reducing or decompressing chamber that is largerin cross section than the injection passage 12. As the pressure reducermeans, however, bifurcating the injection passage 12 is the simplest andquite plain to facilitate manufacturing.

And, in operation of the pest control aerosol sprayer shown, pressingthe operating button 13 in the head cap by a user forces down the stem 5of the valve 3 to open the injection hole 4 in the stem 5 whereby thenoxious insect behavioral inhibitor A contained in the pressure-tightcontainer 1 is forced by its propellant action, namely under gaspressure to flow from the injection hole 4 of the stem 5 in thepressure-tight container 1 into the inflow port 11 and the injectionpassage 12 in the head cap 2, then splitting to flow into the upper andlower injection passages 12 a and 12 b which are bifurcated into as thepressure reducer means in the injection passage 12. Flowing through theupper and lower injection passages 12 a and 12 b, the noxious insectbehavioral inhibitor A is then sprayed forwards from the upper and lowerspray nozzles 10 a and 10 b. And, if the noxious insect behavioralinhibitor A getting into the air adheres to an noxious insect, theinsect will in a moment be refrigerated and terminated of its behavior,i.e., be paralyzed and killed, thus exterminated.

It is noted here that a noxious insect behavioral inhibitor A having analternative for chlorofluorocarbon acting as an active ingredient andalso as a propellant and refrigerant, specifically a noxious insectbehavioral inhibitor A having HFC-152a acting as an active ingredient isconsiderably high in gas pressure, having a gas pressure as high as 4 to5 kgf/cm³ or more (at 25° C.), compared with liquid petroleum gas (LPG)usually used as propellant, which has a gas pressure of 2.8 kgf/cm³ (at25° C.). Another alternative for chlorofluorocarbon has a high gaspressure as well as this. Consequently, spraying the noxious insectbehavioral inhibitor A in an ordinary manner causes the noxious insectbehavioral inhibitor A to be too high in gas pressure at the spraynozzle 10 and to be sprayed in the form of a mist of exceedingly smalldrops or particles, which renders the efficiency of adherence of thenoxious insect behavioral inhibitor to noxious insects low and fails toachieve satisfactory behavioral inhibiting effect. Accordingly, in thepresent invention there is provided a pressure reducer means as apressure dividing mechanism that bifurcates the injection passage 12formed in the head cap 2, thereby enabling the pressure of the gas whensprayed from the spray nozzle 10 to be lowered to some degree. Thisallows the noxious insect behavioral inhibitor A when sprayed throughthe spraying nozzle 10 to be sprayed in the form of coarse mistparticles, thereby increasing the efficiency of its adherence to noxiousinsects and enhancing their refrigerating effect, thus achieving thesatisfactory behavioral inhibiting effect. And, the noxious insectbehavioral inhibitor A when sprayed has an average particle size of 60to 200 μm, preferably 70 to 150 μm. In comparison, an insectifuge havingan ordinary insecticide mixed therein in a conventional pest controlaerosol sprayer has an average particle size of around 20 μm. And, withthe average particle size less than 60 μm, the particles come to soarand scatter along surfaces of noxious insects, and adherence of thenoxious insect behavioral inhibitor A to noxious insects is very poor.

Mention is next made of the content of HFC-152a in the noxious insectbehavioral inhibitor A.

HFC-152a itself acting also as a propellant and refrigerant, it can beused alone in and as the noxious insect behavioral inhibitor A, althougha separate substance or substances can be mixed therewith.

In this case, HFC-152a is contained at a proportion of 75% or more. Inother words, the content of HFC-152a is 75 to 100%.

And, substances that can be mixed in HFC-152a are dimethyl ether, normalbutane, isobutan, propane and their mixed gases as liquefied petroleumgases. But, being flammable, they if mixed much become high inflammability. Thus, when mixed with them, HFC-152a must be of a contentof no less than 75%. If HFC-152a having a content of less than 75% issprayed at a fire origin or the like, it is likely to lead to a backfirecausing a serious problem such as of a fire or burn. Also, whilehydrocarbon normal pentane, isopentane, normal hexane or the like havingthe carbon number of 5 or 6 which is high in boiling point may be mixed,it is high in flammability, requiring its mixing ratio to be set low.Besides, it is possible to mix a compressed gas such as of nitrogen, airor carbon dioxide.

Mention is further made of the content of other than HFC-152a in thenoxious insect behavioral inhibitor A. For example, HFO-1234ze with theaforementioned flammability and likely backfiring problem taken intoaccount can have its content reduced compared with HFC-152a. However,since reducing its content down to less than 50% leads again to theproblem, the content must be 50% or more. In other words, HFO-1234zeneeds to be contained at a proportion of 50 to 100%.

Further, the noxious insect behavioral inhibitor A may have aninsecticide a little intermixed therewith for the purpose of a lethal orrepellent effect. Such insecticides may, for example, be pyrethroidinsecticidal components such as methofluthrin (trade name: Eminence),d1, d-T80-allethrin (trade name: Pynamin Forte), phthalthrin (tradename: Neopynamin), d-T80-phthalthrin (Neopynamine Forte), d,d-T98-prallethrin (trade name; Etoc), d, d-T98 prallethrin (trade name:98 Etoc), d-T80-resmethrin (trade name: Chrysron Forte), transfluthrin(trade name: Biothrin), imiprothrin (trade name: Prone), etofenprox(trade name: Torebon), cyphenothrin (trade name: Gokilaht), d,d-T-cyphenothrin (trade name: Gokilaht S), empenthrin (trade name:Paperthrin), permethrin (trade name: Xmin), phenothrin (trade name:Sumithrin) and pyrethrin (trade name: Chrysanthemum Expel), organicphosphoric insecticidal component such as fenitrothion (trade name:Sumithion) and marathion (trade name: Marathon) and carbamateinsecticidal components such as propoxur (trade name: Baygon) andculverin (trade name: NAG). For natural essential oils can be citedcitronella oil, thyme oil, peppermint oil, lavender oil, coriander oil,cedarwood oil, fennel oil, chamomile oil, cinnamon oil, pimento oil,geranium oil, cumin oil, Japanese peppermint oil, clove oil, hiba oiland lemon grass oil. These components can be used singly or on mixingtwo or more of them, depending on their uses. Such an insecticidalliquid if incorporated should have a content of 0.0001 to 2weight/volume % such as not to adversely affect the human body.

Also, as a solvent it is desirable to use 2,3-dihydrodecafluoropentane(Mitsubishi-Du Pont Fluorochemicals, Co. Ltd., trade name: Vertrel XF)or 1,1-difluoroethane (Sumitomo 3M, Co. Ltd., trade name: <Novec>HFE),which is a nonflammable solvent. By using such a nonflammable solvent,it is possible to provide a pest control aerosol sprayer that isextremely low in dangerousness leading to an explosion or flashing.Further, these solvents have a low boiling point such as to volatilizeat the normal temperature of a room without remaining and withoutleaving dirt of such as a mark of spraying when the sprayer is usedindoors. Moreover, being high in permeability when attached to a noxiousinsect and also having themselves a refrigerating effect, a solvent suchas 2,3-dihydrodecafluoropentane or 1,1-difluoroethane further enhancesthe refrigerating effect on noxious insects and serves to exterminatenoxious insects yet more effectively

Also, using a solvent that is high in both attaching perineability andchoking effect on noxious insects serves to exterminate noxious insectsstill more effectively. For such solvents can be cited, for example,aliphatic, aromatic and cycloaliphatic hydrocarbons, alcohols such asethanol, isopropyl alcohol and methanol, ester, vegetable oils, animaloils and water. Among them, an aliphatic hydrocarbon is excellent ineffects in that by refrigerating at the time of spraying it issolidified and iced, conducing to considerably high low-temperatureretaining effect. However, being hard to volatilize, it has thepossibility that it leaves dirt of a mark of spraying. The solvent istherefore set in at a content of not more than 10% by volume to get ridof dirt by spray marking.

The pest control aerosol sprayer according to the present inventionallows its favorable use indoors because of the property that it leavesno residue of the noxious insect behavioral inhibitor A in an sprayedarea. Noxious insects that can be effectively targeted thereby may becockroaches such as Blattella germanica, Periplaneta fuliginosa,Periplaneta americana, Periplaneta brunnea Burmeister and Periplanetajaponica, spiders, centipedes, ants and stinkbugs. These noxiousinsects, of course, include also flying insects including flies such asMusca domenstica, Fannia canicularis, Sarcophagidae, Aldrichina grahami,Drosophila melanogaster, Psychodidae and Phoridae, mosquitoes such asCulex pipiens pallens and Aedes albopictus, and flying insects such asbees. The pest control aerosol sprayer of the present invention alsoexhibits a control or repelling effect on pyrethroid resistant noxiousinsects.

The pest control aerosol sprayer according to the present invention canbe used anywhere, i.e., in a variety of places including not only ageneral household including a kitchen where there are foodstuff andtableware and a room where there is a baby or small infant, but also arestaurant, a hospital and the like, and will not be restricted by placeof use.

Mention is next made of test examples of the present invention, althoughthe invention does not intend to be limited to them.

Test Example 1 relates to back-fire tests for the aerosol sprayer usingvarious gases. Specifically, aerosol sprayers loaded with various gasesacting as both propellant and refrigerant were prepared. And, afterthese aerosol sprayers were immersed in a thermostatic bath at 25° C.for 1 hour, each of them was arranged with the flame, as a fire origin,of an ignited burner so that the spray nozzle of its head cap and theflame lied horizontally in the same height. And, each gas was sprayedfrom the spray nozzle of the head cap in the aerosol sprayer for 5seconds towards the flame as the fire origin to check if there was abackfire. This was repeated a plurality of times. Here, the fire originwas spaced from the spray nozzle at a distance of 15 cm and at adistance of 60 cm. Results of the test are shown in Table 1 below.

TABLE 1 15 cm distant from 60 cm distant from Name of Gas Fire OriginFire Origin HFC-152a (100%) Not Backfired Not Backfired HFC-134a (100%)Not Backfired Not Backfired LPG (100%) Backfired Backfired dimethylether Backfired Backfired (100%) isopentane (50%) and BackfiredBackfired LPG (50%)

As the test results, it is shown that with each of LPG, dimethyl ether,and a mixture of isopentane and LPG, there was a backfire for both 15 cmand 60 cm distant from the fire origin. Moreover, the mixture ofisopentane and LPG gave rise to a large flame. In contrast to these,with each of HFC-152a and HFC-134a there was no backfire for each of 15cm and 60 cm distant from the fire origin. It is thus seen that HFC-152aand HFC-134a as alternatives for chlorofluorocarbon are extremely low inflammability.

Further, HFO-1234ze as another alternative for chlorofluorocarbon wasalso subjected to the same backfire tests as for HFC-152a and HFC-134ain Text Example 1 mentioned above. Results of the test are shown inTable 2.

TABLE 2 15 cm distant from 60 cm distant from Name of Gas Fire OriginFire Origin HFO-1234ze (100%) Not Backfired Not Backfired

In the results of this test, it is shown as in the aforementionedbackfire test that with HFO-1234ze, too, there was no backfire for eachof 15 cm and 60 cm distant from the fire origin. It is thus seen thatHFO-1234ze as an alternative for chlorofluorocarbon is also extremelylow in flammability.

In Test Example 2, aerosol sprayers using HFC-152a as an alternative forchlorofluorocarbon were tested on its content. This, too, relates toback-fire tests. Specifically, aerosol sprayers loaded with HFC-152aalone and mixtures of HFC-15a with LPG or dimethyl ether (in variedmixture ratio) were prepared. And, after these aerosol sprayers wereimmersed in a thermostatic bath at 25° C. for 1 hour, each of them wasarranged with the flame, as a fire origin, of an ignited burner so thatthe spray nozzle of its head cap and the flame lied horizontally in thesame height. And, each gas was sprayed from the spray nozzle of the headcap in the aerosol sprayer for 5 seconds towards the flame as the fireorigin to check if there was a backfire. This was repeated a pluralityof times. Here, the fire origin was spaced from the spray nozzle at adistance of 15 cm. Results of the test are shown in Table 3 below.

TABLE 3 Proportion of Name of 15 cm distant HFC-152a (%) Mixed Gas fromFire Origin 100% Not Back-fired 75% LPG Not Back-fired 50% LPGBack-fired 25% LPG Back-fired 75% dimethyl ether Not Back-fired 50%dimethyl ether Back-fired 25% dimethyl ether Back-fired

As the test results, it is shown that with each of HFC-152a alone and amixture of HFC-152a at its mixing ratio of 75% with LPG or dimethylether, there was no backfire. However, with mixtures of HFC-152a atmixing ratios of 50% and 25% with LPG or dimethyl ether, there was abackfire. From these, it is seen that HFC-152a if its mixing ratio isset at 75 to 100% in its content is reduced in flammability to enhancethe safety.

Further, HFO-1234ze as another alternative for chlorofluorocarbon wasalso tested on its content as in Text Example 2 above. Results of thetest are shown in Table 2. Specifically, aerosol sprayers loaded withHFO-1234ze alone and mixtures of HFO-1234ze with LPG or dimethyl ether(in varied mixture ratio) were prepared. And, after these aerosolsprayers were immersed in a thermostatic bath at 25° C. for 1 hour, eachof them was arranged with the flame, as a fire origin, of an ignitedburner so that the spray nozzle of its head cap and the flame liedhorizontally in the same height. And, each gas was sprayed from thespray nozzle of the head cap in the aerosol sprayer for 5 secondstowards the flame as the fire origin to check if there was a backfire.This was repeated a plurality of times. Here, the fire origin was spacedfrom the spray nozzle at a distance of 15 cm. Results of the test areshown in Table 4 below.

TABLE 4 Proportion of Name of 15 cm distant HFO-1234ze (%) Mixed Gasfrom Fire Origin 100% Not Back-fired 75% LPG Not Back-fired 50% LPG NotBack-fired 75% dimethyl ether Not Back-fired 50% dimethyl ether NotBack-fired

As the test results, it is shown that with each of HFO-1234ze alone andmixtures of HFO-1234ze at its mixing ratios of 75% and 50% with LPG ordimethyl ether, there was no backfire. From this, it is seen thatHFO-1234ze if its mixing ratio is set at 50 to 100% in its content isreduced in flammability to enhance the safety. Also, HFO-1234ze itselfbeing expensive, its mixing with LPG or dimethyl ether makes it possibleto furnish them less expensively. Note further that this leaves theflammability low and gives rise to no problem whatsoever on safety.

In Test Example 3, modes of spraying from the spray nozzle 10 in thehead cap 2 were examined. This is to examine the refrigerating andbehavioral inhibiting effects on a noxious insect by a noxious insectbehavioral inhibitor A which is sprayed from the spray nozzle 10.Specifically, a wooden flooring was prepared on which a glass ring(having a diameter of 9 cm and a height of 6 cm) was placed. Then, a rodhaving a diameter of 3 mm is inserted between the wooden flooring andthe glass ring to form a clearance between them so that sprayed liquiddoes not collect inside of the glass ring. And, one female adult ofPeriplaneta fuliginosa is introduced inside of the glass ring. On theother hand, two different head caps were prepared, one provided with asingle spray nozzle 10 and the other provided with a pressure reducermeans comprising an upper and a lower spray nozzle 10 a and 10 b. And,using them, the noxious insect behavioral inhibitor A is sprayed for 3seconds toward the Periplaneta fuliginosa from a distance of 50 cmtherefrom, and the state of the Periplaneta fuliginosa thereafter(possible knockdown after 2 minutes and after 1 hour and fatality after24 hours) is observed. Further, the minimum temperatures of a targetarea of spraying are measured. And, the room temperature is 25° C., andthe noxious insect behavioral inhibitor A is HFC-152a alone (100%). Thetwo head caps 2, the one with the single spray nozzle 10 and the otherwith the two spray nozzles 10, are made to spray substantially at aidentical rate of spraying. Test results are shown in Table 5 below.

TABLE 5 Biological test (n = 10) Average Rate of Minimum Knockdown rateFatality Spray particle spray temperature after 2 after 1 after 24 statesize (μm) (g/sec) (° C.) minutes hour hours Single Fine mist 57 3.7−38.6 90% 40% 10% spray nozzle (1.5 mm diameter) Two Coarse 97 3.6 −58.7100% 100% 100% spray mist nozzles Upper nozzle (1.5 mm diameter) Lowernozzle (1.8 mm diameter)

The test results indicate that the head cap provided with two spraynozzles 10, i.e., equipped with a pressure reducer means as a pressuredividing mechanism that bifurcates the injection passage 12 to reducethe pressure of gas to some degree as it is sprayed from the cap, makesthe sprayed mist coarser and the average mist particle size larger, andfurther makes the minimum temperature at the target area of sprayinglower, than with the head cap having a single spray nozzle. Thisincreases the efficiency of adherence of the noxious insect behavioralinhibitor A on a noxious insect and enhances the refrigerating effect,thereby achieving satisfactory noxious insect behavioral inhibitingeffects. Note in this connection that with the head cap with a singlespray nozzle alone, gas pressure is excessive, making mist drops finerand making their adherence on the insect inferior; as a result, sprayingin a short period has failed to achieve satisfactory noxious insectbehavioral inhibiting effects. Moreover, an excessively energetic spraymay have driven the noxious insect to fly off.

Also, in Test Example 3, noxious insect behavioral inhibitors containingHFO-1234ze alone (100%), at a content of 75% and at a content of 50%were examined. What is mixed is dimethyl ether. Test results are shownin Table 6 below.

TABLE 6 Name HFO- of Average Biological test (n = 10) 1234ze mixedparticle Rate of Min. Knockdown rate Fatality content gas Spray sizespray temp. after after after 24 (%) (%) state (μm) (g/sec) (° C.) 2minutes 1 hour hours Two 100% None Coarse 120 4.33 −53.7 100% 100% 60%spray mist nozzles 75% di- Coarse 115 3.75 −52.6 100% 100% 100% Uppermethyl mist nozzle ether (1.5 mm (25%) diameter) 50% di- Coarse 109 3.52−52.7 100% 100% 100% Lower methyl mist nozzle ether (1.8 mm (25%)diameter)

From these test results it is seen, too, that the head cap provided withtwo spray nozzles 10, i.e., equipped with a pressure reducer means as apressure dividing mechanism that bifurcates the injection passage 12 toreduce to some degree the pressure of gas as it is sprayed from the cap,makes the sprayed mist coarser and the average mist particle sizelarger, and further makes the minimum temperature at the target area ofspraying lower. This increases the efficiency of adherence of thenoxious insect behavioral inhibitor A on a noxious insect and enhancesthe refrigerating effect, thereby achieving satisfactory noxious insectbehavioral inhibiting effects. It is further seen that ones withHFO-1234ze at 75% and 50% achieve still higher behavioral inhibitingeffects.

What is claimed is:
 1. A pest control aerosol sprayer, comprising: apressure-tight container which receives therein a noxious insectbehavioral inhibitor of which an active ingredient is an alternative forchlorofluorocarbon acting also as both a propellant and refrigerant, thepressure-tight container having at a top thereof a valve provided with astem, the stem having an injection hole that is openable when the stemis forced down; and a head cap which is attached to a top of thepressure-tight container and which is provided with a spray nozzle andan inflow port in which the stem of the valve in the pressure-tightcontainer is fitted, the head cap including an injection passage leadingfrom the inflow port to the spray nozzle; wherein the alternative forchlorofluorocarbon that is the active ingredient of the noxious insectbehavioral inhibitor is HFC-152a, the HFC-152a being contained at aproportion of no less than 75% and being mixed with liquefied petroleumgas or dimethyl ether.
 2. A pest control aerosol sprayer, comprising: apressure-tight container which receives therein a noxious insectbehavioral inhibitor of which an active ingredient is an alternative forchlorofluorocarbon acting also as both a propellant and refrigerant, thepressure-tight container having at a top thereof a valve provided with astem, the stem having an injection hole that is openable when the stemis forced down; and a head cap which is attached to the top of thepressure-tight container and which is provided with a spray nozzle andan inflow port in which the stem of the valve in the pressure-tightcontainer is fitted, the head cap including an injection passage leadingfrom the inflow port to the spray nozzle; wherein the alternative forchlorofluorocarbon that is the active ingredient of the noxious insectbehavioral inhibitor is HFO-1234yf, the HFO-1234yf being contained at aproportion of no less than 50% and being mixed with liquefied petroleumgas or dimethyl ether.
 3. A pest control aerosol sprayer, comprising: apressure-tight container which receives therein a noxious insectbehavioral inhibitor of which an active ingredient is an alternative forchlorofluorocarbon acting also as both a propellant and refrigerant, thepressure-tight container having at a top thereof a valve provided with astem, the stem having an injection hole that is openable when the stemis forced down; and a head cap which is attached to a top of thepressure-tight container and which is provided with a spray nozzle andan inflow Port in which the stem of the valve in the pressure-tightcontainer is fitted, the head cap including an injection passage leadingfrom the inflow port to the spray nozzle; wherein the alternative forchlorofluorocarbon that is the active ingredient of the noxiousinsect-behavioral inhibitor is HFO-1234ze, the HFO-12324ze beingcontained at a proportion of no less than 50% and being mixed withliquified petroleum gas or dimethyl ether.